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Synthesis of isothiazoles

Recent Literature

A base-promoted demethoxylative cycloaddition of alkynyl oxime ethers enables the synthesis of isoselenazoles and isothiazoles by using cheap and inactive Se powder or Na₂S as selenium and sulfur sources. This one pot transformation offers excellent functional group tolerance.
Z.-Z. Zhang, R. Chen, X.-H. Zhang, X.-G. Zhang, J. Org. Chem., 2021, 86, 632-642.

A Rh-catalyzed transannulation of 1,2,3-thiadiazoles with alkyl, aryl, and heteroaryl nitriles provides a wide variety of isothiazoles via an α-thiavinyl Rh-carbenoid intermediate.
B. Seo, Y. G. Kim, P. H. Lee, Org. Lett., 2016, 18, 5050-5053.

Three-component reactions of enaminoesters, fluorodibromoiamides/ester, and sulfur provide thiazoles and isothiazoles via two C-F bond cleavages along with the formation of new C-S, C-N, and N-S bonds. Both methods offer high selectivity for the synthesis of thiazoles/isothiazoles, which have vital applications in drug discovery and development.
X. Ma, X. Yu, H. Huang, Y. Zhou, Q. Song, Org. Lett., 2020, 22, 5284-5288.

An operationally simple and user-friendly synthesis of 3,5-disubstituted/annulated isothiazoles from β-ketodithioesters/β-ketothioamides and NH₄OAc via C=O/C=S bond functionalization under metal- and catalyst-free conditions. The carbon-economic [4 + 1] annulation relies on a sequential imine formation/cyclization/aerial oxidation cascade forming consecutive C-N and S-N bonds in one pot.
G. Shukla, A. Srivastava, M. S. Singh, Org. Lett., 2016, 18, 2451-2454.